Prior attempts at coating support structures having a low thermal mass with dielectric foam, such as the fine wire inner conductor or plastic rod inner conductor support of a coaxial cable, have suffered from an unacceptably high number of longitudinal voids in the applied dielectric foam, proximate the support structure.
A prior art coaxial cable with void(s) 5 around the fine wire inner conductor 10, for example as shown in FIG. 1, is difficult to prepare for interconnection because the exact inner conductor position is variable. Also, in contrast to a cable where the inner conductor 10 is fully supported by the foam dielectric 15, any pressure upon the inner conductor 10 during interconnection may cause it to bend and collapse into the void(s) 5, away from the cable end.
Commonly owned U.S. Pat. No. 6,800,809, titled “Coaxial Cable and Method of Making Same”, by Moe et al, issued Oct. 5, 2004, hereby incorporated by reference in the entirety, discloses a coaxial cable structure wherein the inner conductor is formed by applying a metallic strip around a cylindrical filler and support structure comprising a cylindrical plastic rod support structure with a foamed dielectric layer there around. The resulting inner conductor structure has significant materials cost and weight savings compared to coaxial cables utilizing solid metal inner conductors.
Competition within the coaxial cable industry has focused attention upon reducing materials and manufacturing costs, electrical characteristic uniformity, defect reduction and overall improved manufacturing quality control.
Therefore, it is an object of the invention to provide a coaxial cable and method of manufacture that overcomes deficiencies in such prior art.